Next Step 12P troubleshooting

[danielb]

Hi,
just recently I moved location of my engine instrument panel, glow plug solenoid, as well replacing some other engine related wiring.
Everything was carefully documented, and reconnected as before.

Since then however my Next step 12P has been throwing the 'Batt Volts Disconnected' error, according to the fault LEDs.
This results in only momentary field output, which is turned off after a couple of seconds after engine is started. So no charging. A side effect being loss of tacho too, as its driven by 'w' terminal.

I went through the Ample Power Troubleshooting guide and filled out the table they provide. It all came out OK, most notably the test at 'Bat. Volts' terminal showed 12.8v (12.3v with ign on, due to glow plugs), so clearly seeing battery voltage.

Not sure where else to look. I've checked all the connections per my notes (and per Ample Power diagram), and made sure they are all making good contact.
Anyone have any thoughts on where else to check? Thanks.

btw, alternator is a little Valeo of about 60A, with external rectification to keep it cooler.